Unveiling the Efficiency of Psychrophillic Aporrectodea caliginosa in Deciphering the Nutrients from Dalweed and Cow Manure with Bio-Optimization of Coprolites

Abstract

There is an immense demand for vermicomposting employing psychrophilic vermiculture (Aporrectodea caliginosa) for management of wastes under the Himalayan ecosystem. Dalweed (weeds from the world-famous urban Dal Lake) and cow manure (CM) are cheaply and abundantly available bio resources in Kashmir valley. Dalweed (DW), disposed of in the heart of the city, ascribes unpleasant effects on tourism and the natural ecosystem. Initial substrate mixtures of DW and CM with different ratios (CM₁₀₀, DW₁₀₀, CM₈₀:DW₂₀, CM₆₀:DW₄₀, CM₄₀:DW₆₀ and CM₂₀:DW₈₀) and castings harvested were analyzed for the following parameters: pH, TOC, TN, NO₃^- P, K, Fe, Zn, C:N, C:P, and C:S ratio. The results of a 56day study revealed in consistency and disparity towards the bio-optimization of coprolites depending upon the type of waste residue and mixture ratio used. Treatments with medium to low dalweed residues (CM₆₀:DW₄₀ followed by CM₈₀:DW₂₀) were found to be optimum and significantly primed chemical properties of castings using A. caligenosa. C:N, C:P, and C:S ratios showed a non-linear response with maximum decrease in C:N ratio by 35%, C:P ratio by 38% in CM₁₀₀, and C:S ratio by 67% in DW₁₀₀. Humification ratio, humification index, and percent humic acids were changed across all the treatments with the highest respective values of 21.33 ± 1.05, 11.33 ± 0.76, and 47.83 ± 0.76 for CM₆₀:DW₄₀. Results also showed that the earthworm population and biomass significantly increased with the highest respective increments of 57.53% and 74.88% in CM₆₀:DW₄₀ over initial values. Moreover, the highest number of cocoons (95.67 ± 1.17) were recorded within CM₆₀:DW₄₀ and the lowest in the control (43.33 ± 1.53). Dehydrogenase and fluorescein diacetate activities were inconsistent with the highest in CM₄₀:DW₆₀ (64.64%) and CM₂₀:DW₈₀ (63.54%) respectively over the initial substrates, while highest urease activity (74.40%) was observed from CM₁₀₀. The results highlight the role of A. caliginosa in sustainable transformation of CM and DW with insightful, beneficial, and priming impacts on castings for its agronomic value.